This invention relates generally to improvements in thermometer devices and, more particularly, to a new and improved temperature sensing probe and disposable probe cover, the probe and cover being adapted for use with an electronic thermometer.
It is common practice in the medical arts, as in hospitals and in doctors' offices, to measure the body temperature of a patient by means of a glass bulb theremometer incorporating a heat responsive mercury column which expands and contracts adjacent a calibrated temperature scale. Typically, the glass thermometer is inserted into the patient, either orally or rectally, and subsequently removed after a sufficient time interval has passed to enable the temperature of the thermometer to stabilize at the body temperature of the patient. This time interval is usually of the order of 2 to 4 minutes. After a sufficient period of time has elapsed, the thermometer is removed from the patient and is subsequently read by appropriate medical personnel.
In order to make another temperature measurement, e.g., either on a second patient or on the same patient at a later time, a second, sterile thermometer must be used, or the first thermometer must be cleaned, sterilized and redistributed prior to reuse.
It will be apparent from the foregoing that conventional temperature measurement procedures using glass bulb thermometers are prone to a number of very significant deficiencies. In this connection, glass bulb thermometers are rather fragile devices which are easily broken and, indeed, such breakage is very common. In addition, temperature measurement is rather slow and, for patients who cannot be relied upon (by virtue of age or infirmity) to properly retain the thermometer for the necessary period of insertion in the body, may necessitate the physical presence of medical personnel during a relatively long measurement cycle, thus wasting valuable time. Furthermore, glass bulb thermometers are not as quick and easy to read, particularly under poor lighting conditions. Moreover, such thermometers require a considerable degree of physical handling by the medical personnel who use them, thus increasing the chances of reinfecting a patient or of cross-contamination between patients. In addition, and as previously pointed out, glass thermometers require a costly sterilization and redistribution process.
Various attempts have been made by the prior art to minimize or eliminate the aforedescribed deficiencies of the glass bulb thermometer by using temperature sensing probes of less fragile construction which are designed to operate in conjunction with direct reading electrical thermometer instrumentation. However, such probes and electrical thermometers have typically proven to be relatively slow in making temperature measurements, and it is still necessary to completely sterilize the probe after each use. Therefore, a large supply of probes is necessary and the relatively expensive sterilization and redistribution costs still remain.
It is also known in the prior art to provide flexible and resilient covers or sheaths for both glass bulb thermometers and electrical probes. However, such prior art devices are still slow and must be physically handled by medical personnel during installation and removal, with the resultant possibility of contamination. Furthermore, such sheaths and covers are generally prone to puncturing, tearing, or being stretched out of shape. In addition, such protective sheaths have not always provided ideal thermal contact between the sheath and the temperature sensing zone of the thermometer or probe and, consequently, the use of such protective sheaths may not produce consistently reliable and accurate results. Moreover, protective sheaths for glass bulb thermometers and electrical probes have typically been rather expensive.
Another solution which has been proposed is the provision of a disposable cover of an electrical probe wherein the cover includes a relatively inexpensive thermally insulating plastic body formed together with a heat conductive metal tip. This arrangement is disclosed thoroughly in U.S. Pat. No. 3,738,479, and although this arrangement functions satisfactorily, forming the cover with a body and tip portion of dissimilar materials is costly and increases the expense of employing the device. Moreover, the arrangement described in that patent includes an electrical probe having a spring biased probe shaft mounted for axial reciprocation with respect to the probe body, thereby adding further to the cost and complexity of the device.
Accordingly, in an effort to reduce the costs of medical care, there exists a need for a truly inexpensive temperature sensing probe and disposable probe cover which provide accurate, reliable, rapid and easily obtained readings, and which obviate the problems of breakage, sterilization, redistribution, and contamination. As will become apparent from the following, the present invention satisfies that need.